#include beep
#operator aPoint
#type 'point
#operator aLine
#type 'line
#operator horiz prefix

#trace		.. turn debugging on

aPoint { x: aNumber ; y: aNumber; true } 'point
aLine { p: aPoint ; q: aPoint; true } 'line
horiz l'line {l.p.y = l.q.y}

main { t: aLine; horiz t }
